Tire Radius Determination and Pressure Loss Detection Using GPS and Vehicle Stability Control Sensors

Abstract

In this work a method of using GPS and vehicle safety sensors to detect faults in a commercial vehicle are presented. In this case, the fault being detected is a loss of tire pressure. The method uses GPS to detect tire pressure changes and is based on the hypothesis that the effective tire radius varies according to tire pressure. The algorithm, which uses GPS and wheel speed signals to estimate the effective radius of the tires, is discussed and validated in simulation and experiment. The algorithm is based on Kalman filter theory and operates on the assumption that there is no wheel slip, which is valid for the un-driven wheels when the vehicle is not braking. Experiments are given to show how the radius estimate varies according to tire pressure, and a simple pressure loss detection law is presented. Experiments are also shown which illustrate how pressure loss in the driven wheels can be detected even when the no slip assumption is violated.